Can the Plane Doors be Opened Mid-Flight?
No, the airplane door cannot be opened when it’s mid-flight. For one, it’s locked but the other reason is physics-based. As you go higher, the air pressure decreases making it harder for us to breathe. This is why the cabin is pressurized to mimic what conditions are like at 8000 feet. The higher pressure within the cabin is what seals the doors shut.
Think of the doors as giant bathtub-drain stoppers. You would need someone who is strong enough to move more than 24,000 pounds to be able to open that door! While the pressure difference decreases as you descend, it’s still too much for a person to overcome. Having said that, “explosive decompression” could cause your door to fly open much like what we see in the movies.